diff options
| author | Avi Kivity <avi@qumranet.com> | 2007-07-19 15:30:14 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-07-20 01:37:05 +0400 |
| commit | 2d9ce177e68645945e3366cfe2d66ee3c28cd4f2 (patch) | |
| tree | a98a3a8b0f1e92f0b8f9ecb44b67bb46c3b4451a /include/asm-i386/cmpxchg.h | |
| parent | 3e1f900bff40460d7bbab0ccd1a9efc3c70aee49 (diff) | |
| download | linux-2d9ce177e68645945e3366cfe2d66ee3c28cd4f2.tar.xz | |
i386: Allow KVM on i386 nonpae
Currently, CONFIG_X86_CMPXCHG64 both enables boot-time checking of
the cmpxchg64b feature and enables compilation of the set_64bit() family.
Since the option is dependent on PAE, and since KVM depends on set_64bit(),
this effectively disables KVM on i386 nopae.
Simplify by removing the config option altogether: the boot check is made
dependent on CONFIG_X86_PAE directly, and the set_64bit() family is exposed
without constraints. It is up to users to check for the feature flag (KVM
does not as virtualiation extensions imply its existence).
Signed-off-by: Avi Kivity <avi@qumranet.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/asm-i386/cmpxchg.h')
| -rw-r--r-- | include/asm-i386/cmpxchg.h | 14 |
1 files changed, 5 insertions, 9 deletions
diff --git a/include/asm-i386/cmpxchg.h b/include/asm-i386/cmpxchg.h index 7adcef0cd53b..64dcdf46117b 100644 --- a/include/asm-i386/cmpxchg.h +++ b/include/asm-i386/cmpxchg.h @@ -3,14 +3,16 @@ #include <linux/bitops.h> /* for LOCK_PREFIX */ +/* + * Note: if you use set64_bit(), __cmpxchg64(), or their variants, you + * you need to test for the feature in boot_cpu_data. + */ + #define xchg(ptr,v) ((__typeof__(*(ptr)))__xchg((unsigned long)(v),(ptr),sizeof(*(ptr)))) struct __xchg_dummy { unsigned long a[100]; }; #define __xg(x) ((struct __xchg_dummy *)(x)) - -#ifdef CONFIG_X86_CMPXCHG64 - /* * The semantics of XCHGCMP8B are a bit strange, this is why * there is a loop and the loading of %%eax and %%edx has to @@ -65,8 +67,6 @@ static inline void __set_64bit_var (unsigned long long *ptr, __set_64bit(ptr, (unsigned int)(value), (unsigned int)((value)>>32ULL) ) : \ __set_64bit(ptr, ll_low(value), ll_high(value)) ) -#endif - /* * Note: no "lock" prefix even on SMP: xchg always implies lock anyway * Note 2: xchg has side effect, so that attribute volatile is necessary, @@ -252,8 +252,6 @@ static inline unsigned long cmpxchg_386(volatile void *ptr, unsigned long old, }) #endif -#ifdef CONFIG_X86_CMPXCHG64 - static inline unsigned long long __cmpxchg64(volatile void *ptr, unsigned long long old, unsigned long long new) { @@ -289,5 +287,3 @@ static inline unsigned long long __cmpxchg64_local(volatile void *ptr, ((__typeof__(*(ptr)))__cmpxchg64_local((ptr),(unsigned long long)(o),\ (unsigned long long)(n))) #endif - -#endif |